1. Field of the Invention
The present invention relates to a light emitting device that can be used in an indicator, a lighting apparatus, a display, a backlight for liquid crystal display etc., and more particularly to a light emitting device excellent in light extraction efficiency in which high reliability can be obtained even when a semiconductor light emitting device having high output is mounted.
2. Background Information
In recent years, various light emitting devices using a semiconductor light emitting element (hereinafter, may be referred to as a light emitting element) have been developed, and methods to improve output have been explored.
For example, JP2004-265979A describes provision of reflector as close as possible to the light emitting element between a light emitting element and a wiring land provided on a substrate to obtain a high luminance.
However, in a case where such a reflector is provided, in order to prevent a light emitting element and a conductive wire from being damaged, a certain distance is required between such electronic components and the reflector. Thus, downsizing is difficult and the size of the light emitting device is limited. Further, the light emitting element and the reflector are set apart, which may cause a reduction of the light extracting efficiency. Particularly, in a case where a gold wire is used to electrically connect a light emitting element to each terminal, gold absorbs light from the light emitting element and a longer wire is required when the reflector is provided as described above. Thus, the absorption of light increases and the output of light decreases.
In addition, a light emitting diode which is a light emitting element is dipolar element. Therefore, an insulating portion is needed between the positive and negative wiring lands (conductor wiring) provided on the substrate. Typically, the insulating portion can be easily provided by exposing an insulating substrate material of the substrate, or the like. However, various limitations are set on an insulating substrate material so as to produce packages efficiently or to secure mechanical strength, or the like. Therefore a material having a desired optical properties (optical reflectivity and optical absorptance) has not always been used.